1. Field of the Invention
The invention relates to new organosilicon compounds. It further relates to preparations for finishing fibers, which contain these new compounds, whereby the preparations are suitable especially for finishing synthetic fibers obtained from melt spinning and, especially, polyester fibers.
2. Description of the Prior Art
Polydimethylsiloxanes are used in spinning plants for finishing melt-spun fibers. Their use for this purpose is possible because of the fact that polydimethylsiloxanes, which are generally referred to simply as silicone oils, endow the treated fibers with a low coefficient of friction, especially at high yarn-take off rates, which coefficient has a slight temperature dependence. In addition, silicone oils are unusually heat stable and have a low viscosity-temperature coefficient.
The finishing of melt-spun yarns directly after their manufacture makes the subsequent drawing and texturizing processes possible. The finish must be effective both as a lubricant and as an antistat. In the thermal fixation processes to which the yarn is subjected, components of the finish are flung off on to the heating unit where they are exposed to heat for a long time. For this reason, the finish must be thermally stable. Those parts of the finish which are deposited on the heating units should, as far as possible, not gel, yellow or evaporate. It is particularly important that there be no gelling.
At the same time, the constituents of the finish should be as compatible as possible with one another. This is a problem especially when it is important to have compatibility between the polar, surface active components, which are primarily responsible for the antistatic effect, and the nonpolar methylsilicone oils, which are primarily responsible for the lubricating properties.
The compatibility of methylsilicone oils can be improved if the methyl groups are partially replaced by longer-chained alkyl groups. The resulting oils are then, however, no longer sufficiently stable thermally. In addition, the viscosity-temperature coefficient of methyl-silicone oils which are modified in such a manner increases greatly.
Even the partial replacement of methyl groups by phenyl groups leads to products with higher viscosity-temperature coefficients whose lubricating properties are impaired.